Fuel cell and process for the production thereof

Abstract

A first gas flow path is formed in a first substrate. The first substrate is processed in an ejection device to form a first collector layer, a first gas diffusion layer, a first reactive layer, and an electrolyte membrane. Similarly, the first substrate is processed to form a second reactive layer, a gas diffusion layer, and a second collector layer. A second substrate which has been processed to form a second gas flow path is then disposed on the first substrate to complete production of a fuel cell having a gas flow path formed therein the opening width of which is smaller than the particle diameter of the material constituting the gas diffusion layer.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of Invention[0002]The present invention relates to a fuel cell which undergoes reaction of various kinds of reactive gases supplied into the respective electrodes to generate electricity and a process for the production thereof.[0003]2. Description of Related Art[0004]Heretofore, there have been fuel cells including an ion-permeable electrolyte provided interposed between porous electron-permeable electrodes. Among these fuel cells are those which use hydrogen, natural gas, alcohol or the like as a fuel to generate electricity. Among these fuel cells, the fuel cell which uses, for example, hydrogen as a fuel receives a first reactive gas containing hydrogen in one electrode and a second reactive gas containing oxygen in the other electrode to generate electricity by the reaction of the hydrogen contained in the first reactive gas with the oxygen contained in the second reactive gas.[0005]The substrate of the fuel cell has a gas flow path for...

AI Technical Summary

Benefits of technology

[0012]An aim of the invention is to provide a fuel cell having a gas flow path formed therein provided with a space through which a reactive gas flows and a process for the production thereof, a fuel cell having an enhanced efficiency of reaction of reactive gas supplied through a gas flow path and a process for the production thereof and a fuel cell which prevents the damage of gas flow path by stress developed by the pressure of reactive gas and exhibits a reduced flow path resistance and a process for the production thereof.

[0037]The process for the production of a fuel cell according to the invention is also characterized in that at least one of the first gas flow path forming step and the second gas flow path forming step can include forming a gas flow path having a semicircular section. In accordance with this process for the production of a fuel cell, the gas flow path having a semicircular section has a smaller area in contact with reactive gas than the gas flow path having a U-shaped section, making it possible to properly reduce the loss of pressure of reactive gas.

Problems solved by technology

Further, a step of disposing the particulate carbon in the gas flow path is that disadvantageously adds to the number of steps required to produce the fuel cell.

However, since most machines for use in semiconductor process are expensive, the use of these machines increases the production cost.

In the case where a gas flow path is formed on the substrate using MEMS, it is necessary that a job of contact-bonding an electrolyte membrane to the substrate be separately effected after the formation of the gas flow path in the substrate, which complicates the production procedure.

Therefore, the supplied amount of the reactive gas varies from upstream to downstream, causing the deterioration of the electricity-generating efficiency of the fuel cell.

However, the reactive layer exhibits a reduced reaction efficiency on the area where the reactive gas is less supplied.

Thus, platinum spread over this area doesn't effectively act as a catalyst.

Further, stress developed by the pressure of the reactive gas is applied to the gas flow path, possibly causing the damage of the gas flow path.

As a result, the wall of the gas flow path shown by the letter L in the drawing can be broken, damaging the gas flow path.

Moreover, the gas flow path having a U-shaped section has a great area in contact with the reactive gas, and hence a raised resistance to the reactive gas, causing a great pressure loss of the reactive gas.

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